7 piece set includes bits for drilling pilot holes for screw sizes 3mm, 4mm, 5mm, 6mm,7mm,8mm,10mm
The woodworking drill is made of HSS 4241, the middle chamfer drill body is NO. 45 steel.
Adjustable counter sleeve depth with wrench.Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew.
Chamfer is 5 flutes,In the process of using, can discharge the wood more rapid, sink hole disposable drilled smooth, screw cap perfect embedded in the surface of workpiece.
It is suitable for drilling machines with chuck, for drilling on hard wood or wooden floor.